Comment by tankenmate

"Because the index needs accuracy.", and I would argue that include price accuracy not just inclusion accuracy. The S&P is a benchmark that is designed to reflect a subset of the market, and giving only some companies early access to the benchmark changes the benchmark. So if you want a benchmark that's designed to include all the big stocks regardless of age, profitability, etc then go make a new benchmark. The only thing you need to do is convince others to use your benchmark.